DNS Study on Hairpin Vortex Structure in Turbulence

Size: px
Start display at page:

Download "DNS Study on Hairpin Vortex Structure in Turbulence"

Transcription

1 DNS Study on Hairpin Vortex Structure in Turbulence Chaoqun Liu Yonghua Yan Hassan Al-dujaly Technical Report

2 DNS Study on Hairpin Vortex Structure in Turbulence Chaoqun Liu, Yonghua Yan, Hassan Al-dujaly University of Texas at Arlington Abstract A forest of hairpin vortices has been accepted widely as the common vortex structure in turbulent flow. It is commonly believed that the hairpin has leg, neck and ring head and the leg is attached on the wall. In our DNS study, it is found that the leg and ring head are separated and generated by different mechanisms. In addition, the ring head is Omega-shaped and separated from the leg and the leg is detached from the wall from beginning. The leg is not a vortex tube in any sense. I. Introduction A forest of hairpin vortices has been accepted widely as the common vortex structure in a turbulent flow (Wu and Moin, 009.) Hairpin vortex (Figure 1)was found by Theodorsen (195) and is widely believed has leg, neck and ring head(figure.) They are three parts of a hairpin vortex as an integrated one. However, this will raise several questions: 1. Since the hairpin vortex has to be stretched, it will have to break down as the leg is placed on the wall surface where velocity is zero and the ring head is located almost near the inviscid area where the streamwise velocity is one unit. Rist et al (00) believe the hairpin vortex will break down and reconnect. The vortex breakdown concept will directly violate the Helmoholtz vortex conservation law and there is no way to reconnect.. In order to explain the vortex package development, Adrian (007) believes that the vortex is original attached on the wall and then detached from the wall. It is really hard to believe how the vortex leg is originally linked with wall surface and then detached from the wall. It sounds that we have no mechanism to perform the process from attachment to detachment. 3. Adrian (007) believes that the vortex package with multiple vortex rings is auto-generated. We must be very careful to use the word auto-generation since everything must be generated with certain mechanism and, in general, cannot be auto-generated. 4. Wallace (011) in his review paper addressed: there has been remarkable progress in turbulent boundary layer research in the past 50 years, particularly in understanding the structural organization of the flow. Consensus exists that vortices drive momentum transport but not about the exact form of the vortices or how they are created and sustained. If we believe the hairpin is an integrated body, it looks like there is no way to understand the turbulence generation. We recently launched a high order DNS to study the hairpin vortex structure carefully and has quite a few new findings on the hairpin vortex generation mechanism and hairpin vortex structure. 1

3 Figure 1: Hairpin vortex (Theodorsen, 195) Figure : Hairpin vortex structure (Moin, 009) II Preliminary Computational Results and Analysis 1. Hiarpin vortex is not a vortex tube A vortex tube cannot be penetrated by vortex filaments, but the hairpin leg are penetrated by many vorticity lines, which clearly shows the vortex leg is not a vortex tube in any sense. Hairpin vortex legs are rotation cores or clustering of vortex filaments (Figure 3). Hiarpin ring head is separated from leg with an Omega shape

4 We use the λ iso-surface at λ = to capture the hairpin vortex head and then trace the origin of the vorticity lines which consist of the ring-like head. We found that the ring-like head is Omega-shaped and separated from hairpin legs (Figure 4.) They are two separated parts and are generated by different mechanism as we reported in last year (Liu et al, 013) 3. Hairpin vortex are never attached with the wall surface If the hairpin vortex leg is attached on the wall surface, it must lead to vortex breakdown due to the zero velocity on the wall and fast moving of the ring head, which will directly violate the Helmoholtz vortex conservation law. Actually, the vortex leg is a concentration of more local vortex filaments. None of these filaments which consist of vortex leg are attached with the wall surface. They are all free to move. The ring head is generated by the shear layer located above the vortex leg by ejection (Liu et al 013.) The ring-like head is separated from the leg and is completely free to move with a fast speed and stretch due to the higher speed on the boundary layer top and fluid deformation. (a) (b) Figure 3: Vortex filaments originate from the cores of Λ -vortex (a) λ -isosurface and vortex filaments; (b) with more vortex filaments on each cross section (a) λ iso-surface (b) Origin of the vorticity Figure 4: The vorticity origin of the first vortex rings 3

5 (a) λ iso-surface (b) Origin of the vorticity of vortex rings Figure 5: The vorticity origin of the multiple vortex rings III Important conclusions Vortex ring head and vortex leg of the hairpin vortex are two separated parts. Vortex legs are not vortex tube. None of the vortex filaments which consist of the hairpin vortex are attached with the wall surface from beginning. They are all from spanwise boundaries and free to move with different speeds, higher on top and lower in bottom. There is no vortex breakdown and no any process from vortex attachment to detachment. In addition, the multiple vortex rings cannot be auto-generated and all of them are generated by shear layer instability (Liu et al 013.) IV Future work More detailed description of the DNS results and analysis will be given in the final AIAA paper. Reference [1] Adrian, R. J., Hairpin vortex organization in wall turbulence, Physics of Fluids, Vol 19, , 007 [] Liu, C. and Yan, Y., DNS Study of Turbulence Structure in a Boundary layer, AIAA , January 13-17, 014, Maryland, USA [3] Rist, U., et al. Turbulence mechanism in Klebanoff transition: a quantitative comparison of experiment and direct numerical simulation. J. Fluid Mech. 00, 459, pp [4] Wallace, J.M., Highlights from 50 years of turbulent boundary layer research, Journal of Turbulence Vol. 13, No. 53, 013, 1 70 [5] Wu, X. and Moin, P., Direct numerical simulation of turbulence in a nominally zero-pressure gradient flat-plate boundary layer, JFM, Vol 630, pp5-41, 4

DNS Study on Three Vortex Identification Methods

DNS Study on Three Vortex Identification Methods Γ DNS Study on Three Vortex Identification Methods Yinlin Dong Yong Yang Chaoqun Liu Technical Report 2016-07 http://www.uta.edu/math/preprint/ DNS Study on Three Vortex Identification Methods Yinlin Dong

More information

High Swept-back Delta Wing Flow

High Swept-back Delta Wing Flow Advanced Materials Research Submitted: 2014-06-25 ISSN: 1662-8985, Vol. 1016, pp 377-382 Accepted: 2014-06-25 doi:10.4028/www.scientific.net/amr.1016.377 Online: 2014-08-28 2014 Trans Tech Publications,

More information

Influence of rounding corners on unsteady flow and heat transfer around a square cylinder

Influence of rounding corners on unsteady flow and heat transfer around a square cylinder Influence of rounding corners on unsteady flow and heat transfer around a square cylinder S. K. Singh Deptt. of Mech. Engg., M. B. M. Engg. College / J. N. V. University, Jodhpur, Rajasthan, India Abstract

More information

Wind tunnel effects on wingtip vortices

Wind tunnel effects on wingtip vortices 48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition 4-7 January 2010, Orlando, Florida AIAA 2010-325 Wind tunnel effects on wingtip vortices Xin Huang 1, Hirofumi

More information

Forest Winds in Complex Terrain

Forest Winds in Complex Terrain Forest Winds in Complex Terrain Ilda Albuquerque 1 Contents Project Description Motivation Forest Complex Terrain Forested Complex Terrain 2 Project Description WAUDIT (Wind Resource Assessment Audit and

More information

Turbulent Coherent Structures under Breaking Water Waves

Turbulent Coherent Structures under Breaking Water Waves Turbulent Coherent Structures under Breaking Water Waves Rozita Jalali Farahani Civil Engineering Department Johns Hopkins University Baltimore, USA rozita@jhu.edu Robert A. Dalrymple Civil Engineering

More information

NUMERICAL SIMULATION OF ACTIVE FLOW CONTROL BASED ON STREAMWISE VORTICES FOR A BLUNT TRAILING EDGE AIRFOIL

NUMERICAL SIMULATION OF ACTIVE FLOW CONTROL BASED ON STREAMWISE VORTICES FOR A BLUNT TRAILING EDGE AIRFOIL BBAA VI International Colloquium on: Bluff Bodies Aerodynamics & Applications Milano, Italy, July, 20-24 2008 NUMERICAL SIMULATION OF ACTIVE FLOW CONTROL BASED ON STREAMWISE VORTICES FOR A BLUNT TRAILING

More information

et al. [25], Noack et al. [26] for circular cylinder flows, Van Oudheusden [27] for square cylinder and Durgesh [28] for a flat plate model. The first two modes appear as phase-shifted versions of each

More information

Numerical Simulation And Aerodynamic Performance Comparison Between Seagull Aerofoil and NACA 4412 Aerofoil under Low-Reynolds 1

Numerical Simulation And Aerodynamic Performance Comparison Between Seagull Aerofoil and NACA 4412 Aerofoil under Low-Reynolds 1 Advances in Natural Science Vol. 3, No. 2, 2010, pp. 244-20 www.cscanada.net ISSN 171-7862 [PRINT] ISSN 171-7870 [ONLINE] www.cscanada.org *The 3rd International Conference of Bionic Engineering* Numerical

More information

Wake modelling for offshore wind turbine parks. Jens N. Sørensen Department of Wind Energy Technical University of Denmark

Wake modelling for offshore wind turbine parks. Jens N. Sørensen Department of Wind Energy Technical University of Denmark Wake modelling for offshore wind turbine parks Jens N. Sørensen Department of Wind Energy Technical University of Denmark Wake and Wind Farm Aerodynamics Basic questions and issues: How important is the

More information

Avai 193 Fall 2016 Laboratory Greensheet

Avai 193 Fall 2016 Laboratory Greensheet Avai 193 Fall 2016 Laboratory Greensheet Lab Report 1 Title: Instrumentation Test Technique Research Process: Break into groups of 4 people. These groups will be the same for all of the experiments performed

More information

STUDY OF MICROBUBBLES FOR SKIN-FRICTION DRAG REDUCTION. *

STUDY OF MICROBUBBLES FOR SKIN-FRICTION DRAG REDUCTION. * STUDY OF MICROBUBBLES FOR SKIN-FRICTION DRAG REDUCTION Yan Yao 1 *, Jin-ling Luo 1,Kun Zhu 1, Hai-bo He 1, Rui Wu 2, Shi-jie Qin 3 1 Beijing Electromechanic Engineering Institute, Beijing, 100074, China

More information

NUMERICAL INVESTIGATION OF AERODYNAMIC CHARACTERISTICS OF NACA AIRFOIL WITH A GURNEY FLAP

NUMERICAL INVESTIGATION OF AERODYNAMIC CHARACTERISTICS OF NACA AIRFOIL WITH A GURNEY FLAP Int. J. Mech. Eng. & Rob. Res. 2012 MasoudJahanmorad Nouri et al., 2012 Research Paper ISSN 2278 0149 www.ijmerr.com Vol. 1, No. 3, October 2012 2012 IJMERR. All Rights Reserved NUMERICAL INVESTIGATION

More information

Vortical Patterns in the Wake of an Oscillating Airfoil

Vortical Patterns in the Wake of an Oscillating Airfoil 1200 AIAA JOURNAL VOL. 27, NO. 9, SEPTEMBER 1989 Vortical Patterns in the Wake of an Oscillating Airfoil Manoochehr M. Koochesfahani* California Institute of Technology, Pasadena, California The vortical

More information

Keywords: dynamic stall, free stream turbulence, pitching airfoil

Keywords: dynamic stall, free stream turbulence, pitching airfoil Applied Mechanics and Materials Vol. 225 (2012) pp 103-108 Online available since 2012/Nov/29 at www.scientific.net (2012) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/amm.225.103

More information

This is the author s final accepted version.

This is the author s final accepted version. Ibrahim, I.H., Joy, J. and New, T.N. (2016) Numerical Investigation on Flow Separation Control of Low Reynolds Number Sinusoidal Aerofoils. In: 46th AIAA Fluid Dynamics Conference, AIAA AVIATION Forum,

More information

Large-eddy simulation study of effects of clearing in forest on wind turbines

Large-eddy simulation study of effects of clearing in forest on wind turbines Large-eddy simulation study of effects of clearing in forest on wind turbines J. Matsfelt 1 and L. Davidson 1 1 Chalmers University of Technology, Dep. of Mechanics and Maritime Sciences, Div. of Fluid

More information

Experimental and Theoretical Investigation for the Improvement of the Aerodynamic Characteristic of NACA 0012 airfoil

Experimental and Theoretical Investigation for the Improvement of the Aerodynamic Characteristic of NACA 0012 airfoil International Journal of Mining, Metallurgy & Mechanical Engineering (IJMMME) Volume 2, Issue 1 (214) ISSN 232 46 (Online) Experimental and Theoretical Investigation for the Improvement of the Aerodynamic

More information

Centre for Offshore Renewable Energy Engineering, School of Energy, Environment and Agrifood, Cranfield University, Cranfield, MK43 0AL, UK 2

Centre for Offshore Renewable Energy Engineering, School of Energy, Environment and Agrifood, Cranfield University, Cranfield, MK43 0AL, UK 2 Fluid Structure Interaction Modelling of A Novel 10MW Vertical-Axis Wind Turbine Rotor Based on Computational Fluid Dynamics and Finite Element Analysis Lin Wang 1*, Athanasios Kolios 1, Pierre-Luc Delafin

More information

Large Eddy Simulation of Wing Tip Vortex in the Near Field

Large Eddy Simulation of Wing Tip Vortex in the Near Field Large Eddy Simulation of Wing Tip Vortex in the Near Field Li Jiang Jiangang Cai Chaoqun Liu Technical Report 2007-13 http://www.uta.edu/math/preprint/ Large Eddy Simulation of Wing Tip Vortex in the Near

More information

Study on wind turbine arrangement for offshore wind farms

Study on wind turbine arrangement for offshore wind farms Downloaded from orbit.dtu.dk on: Jul 01, 2018 Study on wind turbine arrangement for offshore wind farms Shen, Wen Zhong; Mikkelsen, Robert Flemming Published in: ICOWEOE-2011 Publication date: 2011 Document

More information

DOLPHIN HYDRODYNAMICS GRAY S PARADOX REVISITED. Peter W. Carpenter University of Warwick, U.K.

DOLPHIN HYDRODYNAMICS GRAY S PARADOX REVISITED. Peter W. Carpenter University of Warwick, U.K. DOLPHIN HYDRODYNAMICS GRAY S PARADOX REVISITED Peter W. Carpenter University of Warwick, U.K. 3rd International Symp. on Ultrasonic Doppler Methods for Fluid Mechanics & Fluid Engineering EPFL, Switzerland

More information

Numerical Analysis of the Propeller with Economical Cap by CFD

Numerical Analysis of the Propeller with Economical Cap by CFD Numerical Analysis of the Propeller with Economical Cap by CFD 1.Introduction Yoshihisa Okada*, Kenta Katayama* and Akinori Okazaki* Propeller Design department, Nakashima Propeller Co.,Ltd. 688-1, Joto-Kitagata,

More information

Free Surface Flow Simulation with ACUSIM in the Water Industry

Free Surface Flow Simulation with ACUSIM in the Water Industry Free Surface Flow Simulation with ACUSIM in the Water Industry Tuan Ta Research Scientist, Innovation, Thames Water Kempton Water Treatment Works, Innovation, Feltham Hill Road, Hanworth, TW13 6XH, UK.

More information

DUE TO EXTERNAL FORCES

DUE TO EXTERNAL FORCES 17B.6 DNS ON GROWTH OF A VERTICAL VORTEX IN CONVECTION DUE TO EXTERNAL FORCES Ryota Iijima* and Tetsuro Tamura Tokyo Institute of Technology, Yokohama, Japan 1. INTRODUCTION Various types of vertical vortices,

More information

Tim Lee s journal publications

Tim Lee s journal publications Tim Lee s journal publications 82. Lee, T., and Tremblay-Dionne, V., (2018) Impact of wavelength and amplitude of a wavy ground on a static NACA 0012 airfoil submitted to Journal of Aircraft (paper in

More information

CFD SIMULATION STUDY OF AIR FLOW AROUND THE AIRFOIL USING THE MAGNUS EFFECT

CFD SIMULATION STUDY OF AIR FLOW AROUND THE AIRFOIL USING THE MAGNUS EFFECT Magnus effect, simulation, air flow Patryk SOKOŁOWSKI *, Jacek CZARNIGOWSKI **, Paweł MAGRYTA *** CFD SIMULATION STUDY OF AIR FLOW AROUND THE AIRFOIL USING THE MAGNUS EFFECT Abstract The article presents

More information

COMPUTATIONAL FLOW MODEL OF WESTFALL'S LEADING TAB FLOW CONDITIONER AGM-09-R-08 Rev. B. By Kimbal A. Hall, PE

COMPUTATIONAL FLOW MODEL OF WESTFALL'S LEADING TAB FLOW CONDITIONER AGM-09-R-08 Rev. B. By Kimbal A. Hall, PE COMPUTATIONAL FLOW MODEL OF WESTFALL'S LEADING TAB FLOW CONDITIONER AGM-09-R-08 Rev. B By Kimbal A. Hall, PE Submitted to: WESTFALL MANUFACTURING COMPANY September 2009 ALDEN RESEARCH LABORATORY, INC.

More information

Kinematics of Vorticity

Kinematics of Vorticity Kinematics of Vorticity Vorticity Ω Ω= V 2 circumferentially averaged angular velocity of the fluid particles Sum of rotation rates of perpendicular fluid lines Non-zero vorticity doesn t imply spin.ω=0.

More information

Wind Flow Model of Area Surrounding the Case Western Reserve University Wind Turbine

Wind Flow Model of Area Surrounding the Case Western Reserve University Wind Turbine Wind Flow Model of Area Surrounding the Case Western Reserve University Wind Turbine Matheus C. Fernandes 1, David H. Matthiesen PhD *2 1 Case Western Reserve University Dept. of Mechanical Engineering,

More information

Key-Words: - Vortex merger, Self-rotation, Background straining, Vortex core, Vortex filament

Key-Words: - Vortex merger, Self-rotation, Background straining, Vortex core, Vortex filament A comparison between asymmetric and symmetric vortex mergers Mei-Jiau Huang Mechanical Engineering Department National Taiwan University #1 Sec.4 Roosevelt Rd., Taipei Taiwan Abstract: - The dynamics of

More information

A comparison of NACA 0012 and NACA 0021 self-noise at low Reynolds number

A comparison of NACA 0012 and NACA 0021 self-noise at low Reynolds number A comparison of NACA 12 and NACA 21 self-noise at low Reynolds number A. Laratro, M. Arjomandi, B. Cazzolato, R. Kelso Abstract The self-noise of NACA 12 and NACA 21 airfoils are recorded at a Reynolds

More information

GEOMETRY TIP CAP EFFECTS ON FORMATION AND NEAR WAKE EVOLUTION OF THE ROTOR TIP VORTICES

GEOMETRY TIP CAP EFFECTS ON FORMATION AND NEAR WAKE EVOLUTION OF THE ROTOR TIP VORTICES 36th AIAA Fluid Dynamics Conference and Exhibit 5-8 June 2006, San Francisco, California AIAA 2006-3376 GEOMETRY TIP CAP EFFECTS ON FORMATION AND NEAR WAKE EVOLUTION OF THE ROTOR TIP VORTICES Roxana Vasilescu

More information

EXPERIMENTAL ANALYSIS OF THE CONFLUENT BOUNDARY LAYER BETWEEN A FLAP AND A MAIN ELEMENT WITH SAW-TOOTHED TRAILING EDGE

EXPERIMENTAL ANALYSIS OF THE CONFLUENT BOUNDARY LAYER BETWEEN A FLAP AND A MAIN ELEMENT WITH SAW-TOOTHED TRAILING EDGE 24 TH INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES EXPERIMENTAL ANALYSIS OF THE CONFLUENT BOUNDARY LAYER BETWEEN A FLAP AND A MAIN ELEMENT WITH SAW-TOOTHED TRAILING EDGE Lemes, Rodrigo Cristian,

More information

Effect of a single leading-edge protuberance on NACA airfoil performance

Effect of a single leading-edge protuberance on NACA airfoil performance Effect of a single leading-edge protuberance on NACA 63 4-021 airfoil performance Chang Cai 1, Zhigang Zuo 1, Shuhong Liu 1 *, Yulin Wu 1, ISROMAC 2016 International Symposium on Transport Phenomena and

More information

Performance Improvements in Boeing/AFOSR Mach 6 Quiet Wind Tunnel Based on CFD Predictions

Performance Improvements in Boeing/AFOSR Mach 6 Quiet Wind Tunnel Based on CFD Predictions Performance Improvements in Boeing/AFOSR Mach 6 Quiet Wind Tunnel Based on CFD Predictions Hadassah Naiman, Doyle D. Knight Rutgers University Selin Aradag US Air Force Academy Thomas J. Juliano,, Steven

More information

Design And Performance Analysis Of Bump Surface In An Airfoil

Design And Performance Analysis Of Bump Surface In An Airfoil ISSN: 2278 0211 (Online) Design And Performance Analysis Of Bump Surface In An Airfoil Nithya S. School Of Aeronautical Sciences, Hindustan University, India G. Dineshkumar School Of Aeronautical Sciences,

More information

PRESSURE DISTRIBUTION OF SMALL WIND TURBINE BLADE WITH WINGLETS ON ROTATING CONDITION USING WIND TUNNEL

PRESSURE DISTRIBUTION OF SMALL WIND TURBINE BLADE WITH WINGLETS ON ROTATING CONDITION USING WIND TUNNEL International Journal of Mechanical and Production Engineering Research and Development (IJMPERD ) ISSN 2249-6890 Vol.2, Issue 2 June 2012 1-10 TJPRC Pvt. Ltd., PRESSURE DISTRIBUTION OF SMALL WIND TURBINE

More information

Numerical study of Wavy Blade Section for Wind Turbines

Numerical study of Wavy Blade Section for Wind Turbines Journal of Physics: Conference Series PAPER OPEN ACCESS Numerical study of Wavy Blade Section for Wind Turbines To cite this article: C.M Kobæk and M.O.L Hansen 2016 J. Phys.: Conf. Ser. 753 022039 Recent

More information

The Effect of Von Karman Vortex Street on Building Ventilation

The Effect of Von Karman Vortex Street on Building Ventilation The Effect of Von Karman Vortex Street on Building Ventilation P.Praveen Kumar Abstract This paper deals with the utilisation of the von Karman vortex street principle to maximise air flow into buildings.

More information

Computational Analysis of the S Airfoil Aerodynamic Performance

Computational Analysis of the S Airfoil Aerodynamic Performance Computational Analysis of the 245-3S Airfoil Aerodynamic Performance Luis Velazquez-Araque and Jiří Nožička 2 Department of Mechanical Engineering National University of Táchira, San Cristóbal 5, Venezuela

More information

A study of heat transfer effects on air pollution dispersion in street canyons by numerical simulations

A study of heat transfer effects on air pollution dispersion in street canyons by numerical simulations A study of heat transfer effects on air pollution dispersion in street canyons by numerical simulations N. Moussiopoulos, I. Ossanlis and Ph. Barmpas Aristotle University Thessaloniki, Greece MIMO 3D,

More information

Pressure distribution of rotating small wind turbine blades with winglet using wind tunnel

Pressure distribution of rotating small wind turbine blades with winglet using wind tunnel Journal of Scientific SARAVANAN & Industrial et al: Research PRESSURE DISTRIBUTION OF SMALL WIND TURBINE BLADES WITH WINGLET Vol. 71, June 01, pp. 45-49 45 Pressure distribution of rotating small wind

More information

Next Generation Modeling for Deep Water Wave Breaking and Langmuir Circulation

Next Generation Modeling for Deep Water Wave Breaking and Langmuir Circulation Next Generation Modeling for Deep Water Wave Breaking and Langmuir Circulation Eric D. Skyllingstad College of Oceanic and Atmospheric Sciences, Oregon State University Corvallis, OR 97331, Phone: (541)

More information

Anna University Regional office Tirunelveli

Anna University Regional office Tirunelveli Effect of Tubercle Leading Edge Control Surface on the Performance of the Double Delta Wing Fighter Aircraft P Sharmila 1, S Rajakumar 2 1 P.G. Scholar, 2 Assistant Professor, Mechanical Department Anna

More information

Lecture # 08: Boundary Layer Flows and Controls

Lecture # 08: Boundary Layer Flows and Controls AerE 344 Lecture Notes Lecture # 8: Boundary Layer Flows and Controls Dr. Hui Hu Department of Aerospace Engineering Iowa State University Ames, Iowa 511, U.S.A Flow Separation on an Airfoil Quantification

More information

Effects of separation distance on the vortical behaviour of jetimpingement

Effects of separation distance on the vortical behaviour of jetimpingement Effects of separation distance on the vortical behaviour of jetimpingement upon convex cylinders Long Jiao 1,* and New Tze How 1 1: School of Mechanical and Aerospace Engineering, Nanyang Technological

More information

Experimental Investigation Of Flow Past A Rough Surfaced Cylinder

Experimental Investigation Of Flow Past A Rough Surfaced Cylinder (AET- 29th March 214) RESEARCH ARTICLE OPEN ACCESS Experimental Investigation Of Flow Past A Rough Surfaced Cylinder Monalisa Mallick 1, A. Kumar 2 1 (Department of Civil Engineering, National Institute

More information

THE BRIDGE COLLAPSED IN NOVEMBER 1940 AFTER 4 MONTHS OF ITS OPENING TO TRAFFIC!

THE BRIDGE COLLAPSED IN NOVEMBER 1940 AFTER 4 MONTHS OF ITS OPENING TO TRAFFIC! OUTLINE TACOMA NARROWS BRIDGE FLOW REGIME PAST A CYLINDER VORTEX SHEDDING MODES OF VORTEX SHEDDING PARALLEL & OBLIQUE FLOW PAST A SPHERE AND A CUBE SUMMARY TACOMA NARROWS BRIDGE, USA THE BRIDGE COLLAPSED

More information

Enhanced Airfoil Design Incorporating Boundary Layer Mixing Devices

Enhanced Airfoil Design Incorporating Boundary Layer Mixing Devices AIAA-2003-0211 Enhanced Airfoil Design Incorporating Boundary Layer Mixing Devices Michael Kerho and Brian Kramer Rolling Hills Research Corporation Torrance, CA 41st AIAA Aerospace Sciences Meeting &

More information

Unsteady airfoil experiments

Unsteady airfoil experiments Unsteady airfoil experiments M.F. Platzer & K.D. Jones AeroHydro Research & Technology Associates, Pebble Beach, CA, USA. Abstract This paper describes experiments that elucidate the dynamic stall phenomenon

More information

JOURNAL PUBLICATIONS

JOURNAL PUBLICATIONS 1 JOURNAL PUBLICATIONS 71. Lee, T., Mageed, A., Siddiqui, B. and Ko, L.S., (2016) Impact of ground proximity on aerodynamic properties of an unsteady NACA 0012 airfoil, submitted to Journal of Aerospace

More information

Effect of Co-Flow Jet over an Airfoil: Numerical Approach

Effect of Co-Flow Jet over an Airfoil: Numerical Approach Contemporary Engineering Sciences, Vol. 7, 2014, no. 17, 845-851 HIKARI Ltd, www.m-hikari.com http://dx.doi.org/10.12988/ces.2014.4655 Effect of Co-Flow Jet over an Airfoil: Numerical Approach Md. Riajun

More information

Experimental investigation on the aft-element flapping of a two-element airfoil at high attack angle

Experimental investigation on the aft-element flapping of a two-element airfoil at high attack angle Experimental investigation on the aft-element flapping of a two-element airfoil at high attack angle Tan Guang-kun *, Shen Gong-xin, Su Wen-han Beijing University of Aeronautics and Astronautics (BUAA),

More information

Helicopters / Vortex theory. Filipe Szolnoky Cunha

Helicopters / Vortex theory. Filipe Szolnoky Cunha Vortex Theory Slide 1 Vortex Theory Slide 2 Vortex Theory µ=0.2 Slide 3 Vortex Theory µ=0.4 Slide 4 Vortex Theory Slide 5 Tip Vortex Trajectories Top view Slide 6 Definition Wake Age Slide 7 Assumptions:

More information

Simulation of Flow Field Past Symmetrical Aerofoil Baffles Using Computational Fluid Dynamics Method

Simulation of Flow Field Past Symmetrical Aerofoil Baffles Using Computational Fluid Dynamics Method Proceedings of the 4 th International Conference of Fluid Flow, Heat and Mass Transfer (FFHMT'17) Toronto, Canada August 21 23, 2017 Paper No. 120 DOI: 10.11159/ffhmt17.120 Simulation of Flow Field Past

More information

Numerical and Experimental Investigation of the Possibility of Forming the Wake Flow of Large Ships by Using the Vortex Generators

Numerical and Experimental Investigation of the Possibility of Forming the Wake Flow of Large Ships by Using the Vortex Generators Second International Symposium on Marine Propulsors smp 11, Hamburg, Germany, June 2011 Numerical and Experimental Investigation of the Possibility of Forming the Wake Flow of Large Ships by Using the

More information

Numerical Simulation of the Basketball Flight Trajectory based on FLUENT Fluid Solid Coupling Mechanics Yanhong Pan

Numerical Simulation of the Basketball Flight Trajectory based on FLUENT Fluid Solid Coupling Mechanics Yanhong Pan Applied Mechanics and Materials Submitted: 2014-08-05 ISSN: 1662-7482, Vols. 651-653, pp 2347-2351 Accepted: 2014-08-06 doi:10.4028/www.scientific.net/amm.651-653.2347 Online: 2014-09-30 2014 Trans Tech

More information

AERODYNAMIC CHARACTERISTICS OF SPIN PHENOMENON FOR DELTA WING

AERODYNAMIC CHARACTERISTICS OF SPIN PHENOMENON FOR DELTA WING ICAS 2002 CONGRESS AERODYNAMIC CHARACTERISTICS OF SPIN PHENOMENON FOR DELTA WING Yoshiaki NAKAMURA (nakamura@nuae.nagoya-u.ac.jp) Takafumi YAMADA (yamada@nuae.nagoya-u.ac.jp) Department of Aerospace Engineering,

More information

EXPERIMENTAL AND NUMERICAL STUDY OF A TWO- ELEMENT WING WITH GURNEY FLAP

EXPERIMENTAL AND NUMERICAL STUDY OF A TWO- ELEMENT WING WITH GURNEY FLAP 25 TH INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES EXPERIMENTAL AND NUMERICAL STUDY OF A TWO- ELEMENT WING WITH GURNEY FLAP F.M. Catalano PhD.( catalano@sc.usp.br ) *, G. L. Brand * * Aerodynamic

More information

EXPERIMENTAL INVESTIGATION OF WAKE SURVEY OVER A CYLINDER WITH DIFFERENT SURFACE PROFILES

EXPERIMENTAL INVESTIGATION OF WAKE SURVEY OVER A CYLINDER WITH DIFFERENT SURFACE PROFILES EXPERIMENTAL INVESTIGATION OF WAKE SURVEY OVER A CYLINDER WITH DIFFERENT SURFACE PROFILES Abdul Ahad Khan 1, Abhishek M. B 2, Tresa Harsha P George 3 1 Under Graduate student, Department of Aeronautical

More information

VORTEX EVOLUTION BY STRAINING: A MECHANISM FOR DOMINANCE OF STRONG INTERIOR ANTICYCLONES

VORTEX EVOLUTION BY STRAINING: A MECHANISM FOR DOMINANCE OF STRONG INTERIOR ANTICYCLONES VORTEX EVOLUTION BY STRAINING: A MECHANISM FOR DOMINANCE OF STRONG INTERIOR ANTICYCLONES M. Montgomery Naval Post Graduate School & NOAA Hurr. Res. Div. J. McWilliams UCLA L. Graves UCLA Jupiter s Red

More information

Effect of Wavy Trailing Edge on 100meter Flatback Wind Turbine Blade

Effect of Wavy Trailing Edge on 100meter Flatback Wind Turbine Blade Journal of Physics: Conference Series PAPER OPEN ACCESS Effect of Wavy Trailing Edge on 100meter Flatback Wind Turbine Blade To cite this article: SJ Yang and J D Baeder 2016 J. Phys.: Conf. Ser. 753 022060

More information

Figure 1. Outer dimensions of the model trucks.

Figure 1. Outer dimensions of the model trucks. 1 Standardisation of test method for salt spreader: Air flow experiments Report 3: Simulations of airflow patterns by Jan S. Strøm, Consultant Aarhus University, Engineering Centre Bygholm, Test and Development

More information

Dynamic Stall For A Vertical Axis Wind Turbine In A Two-Dimensional Study

Dynamic Stall For A Vertical Axis Wind Turbine In A Two-Dimensional Study Abstracts of Conference Papers: TSBE EngD Conference, TSBE Centre, University of Reading, Whiteknights, RG6 Dynamic Stall For A Vertical Axis Wind Turbine In A Two-Dimensional Study R. Nobile 1,*, Dr M.

More information

IJESRT: 8(1), January, 2019 ISSN:

IJESRT: 8(1), January, 2019 ISSN: IJESRT: 8(1), January, 2019 ISSN: 2277-9655 International Journal of Engineering Sciences & Research Technology (A Peer Reviewed Online Journal) Impact Factor: 5.164 IJESRT Chief Editor Dr. J.B. Helonde

More information

Aerodynamic Analysis of Blended Winglet for Low Speed Aircraft

Aerodynamic Analysis of Blended Winglet for Low Speed Aircraft , July 1-3, 2015, London, U.K. Aerodynamic Analysis of Blended Winglet for Low Speed Aircraft Pooja Pragati, Sudarsan Baskar Abstract This paper provides a practical design of a new concept of massive

More information

Turbulence Modelling of Deep Dynamic Stall at Low Reynolds Number

Turbulence Modelling of Deep Dynamic Stall at Low Reynolds Number , June 30 - July 2, 2010, London, U.K. Turbulence Modelling of Deep Dynamic Stall at Low Reynolds Number Shengyi Wang, Lin Ma, Derek B Ingham, Mohamed Pourkashanian and Zhi Tao Abstract The unsteady separated

More information

An Experimental Study of the Laminar Flow Separation on a Low-Reynolds-Number Airfoil

An Experimental Study of the Laminar Flow Separation on a Low-Reynolds-Number Airfoil An Experimental Study of the Laminar Flow Separation on a Low-Reynolds-Number Airfoil Hui Hu Assistant Professor e-mail: huhui@iastate.edu Zifeng Yang Graduate Student Department of Aerospace Engineering,

More information

EXPERIMENTAL INVESTIGATION OF THE EFFECT OF VARIOUS WINGLET SHAPES ON THE TOTAL PRESSURE DISTRIBUTION BEHIND A WING

EXPERIMENTAL INVESTIGATION OF THE EFFECT OF VARIOUS WINGLET SHAPES ON THE TOTAL PRESSURE DISTRIBUTION BEHIND A WING 24 TH INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES EXPERIMENTAL INVESTIGATION OF THE EFFECT OF VARIOUS WINGLET SHAPES ON THE TOTAL PRESSURE DISTRIBUTION BEHIND A WING Mohammad Reza Soltani, Kaveh

More information

Super-parameterization of boundary layer roll vortices in tropical cyclone models

Super-parameterization of boundary layer roll vortices in tropical cyclone models DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Super-parameterization of boundary layer roll vortices in tropical cyclone models PI Isaac Ginis Graduate School of Oceanography

More information

NUMERICAL INVESTIGATION OF THE FLOW BEHAVIOUR IN A MODERN TRAFFIC TUNNEL IN CASE OF FIRE INCIDENT

NUMERICAL INVESTIGATION OF THE FLOW BEHAVIOUR IN A MODERN TRAFFIC TUNNEL IN CASE OF FIRE INCIDENT - 277 - NUMERICAL INVESTIGATION OF THE FLOW BEHAVIOUR IN A MODERN TRAFFIC TUNNEL IN CASE OF FIRE INCIDENT Iseler J., Heiser W. EAS GmbH, Karlsruhe, Germany ABSTRACT A numerical study of the flow behaviour

More information

Asymmetric vortex shedding flow past an inclined flat plate at high incidence

Asymmetric vortex shedding flow past an inclined flat plate at high incidence Title Asymmetric vortex shedding flow past an inclined flat plate at high incidence Author(s) Lam, KM; Leung, MYH Citation European Journal Of Mechanics, B/Fluids, 5, v. 4 n., p. - 48 Issued Date 5 URL

More information

Numerical and Experimental Investigations of Lift and Drag Performances of NACA 0015 Wind Turbine Airfoil

Numerical and Experimental Investigations of Lift and Drag Performances of NACA 0015 Wind Turbine Airfoil International Journal of Materials, Mechanics and Manufacturing, Vol. 3, No., February 2 Numerical and Experimental Investigations of Lift and Drag Performances of NACA Wind Turbine Airfoil İzzet Şahin

More information

A Study on the Effects of Wind on the Drift Loss of a Cooling Tower

A Study on the Effects of Wind on the Drift Loss of a Cooling Tower A Study on the Effects of Wind on the Drift Loss of a Cooling Tower Wanchai Asvapoositkul 1* 1 Department of Mechanical Engineering, Faculty of Engineering, King Mongkut s University of Technology Thonburi

More information

EXPERIMENTAL AND ANALYTICAL INVESTIGATION OF THE EFFECT OF BODY KIT USED WITH SALOON CARS IN BRUNEI DARUSSALAM

EXPERIMENTAL AND ANALYTICAL INVESTIGATION OF THE EFFECT OF BODY KIT USED WITH SALOON CARS IN BRUNEI DARUSSALAM EXPERIMENTAL AND ANALYTICAL INVESTIGATION OF THE EFFECT OF BODY KIT USED WITH SALOON CARS IN BRUNEI DARUSSALAM M.G., Yazdani, H. Ullah, T. Aderis and R. Zainulariffin, Faculty of Engineering, Institut

More information

Numerical Propeller Rudder Interaction Studies to Assist Fuel Efficient Shipping

Numerical Propeller Rudder Interaction Studies to Assist Fuel Efficient Shipping Numerical Propeller Rudder Interaction Studies to Assist Fuel Efficient Shipping Charles Badoe 1*, Alexander Phillips 1 and Stephen R Turnock 1 1 Faculty of Engineering and the Environment, University

More information

THE FLUID MECHANICS OF VORTEX

THE FLUID MECHANICS OF VORTEX THE FLUID MECHANICS OF VORTEX CUTTING BY A BLADE by Jeffrey S. Marshall Sponsored by U.S. Army Research Office llrrreportno. 363 Iowa Institute of Hydraulic Research The University of Iowa Iowa City, Iowa

More information

Basic Fluid Mechanics

Basic Fluid Mechanics Basic Fluid Mechanics Chapter 7B: Forces on Submerged Bodies 7/26/2018 C7B: Forces on Submerged Bodies 1 Forces on Submerged Bodies Lift and Drag are forces exerted on an immersed body by the surrounding

More information

Hydrogen Bubble Flow Visualization Unit UVF

Hydrogen Bubble Flow Visualization Unit UVF Technical Teaching Equipment Hydrogen Bubble Flow Visualization Unit UVF PROCESS DIAGRAM AND UNIT ELEMENTS ALLOCATION ISO 9001: Quality Management (for Design, Manufacturing, Commercialization and After-sales

More information

ISOLATION OF NON-HYDROSTATIC REGIONS WITHIN A BASIN

ISOLATION OF NON-HYDROSTATIC REGIONS WITHIN A BASIN ISOLATION OF NON-HYDROSTATIC REGIONS WITHIN A BASIN Bridget M. Wadzuk 1 (Member, ASCE) and Ben R. Hodges 2 (Member, ASCE) ABSTRACT Modeling of dynamic pressure appears necessary to achieve a more robust

More information

CFD Analysis of Supersonic Nozzle with Varying Divergent Profile

CFD Analysis of Supersonic Nozzle with Varying Divergent Profile CFD Analysis of Supersonic Nozzle with Varying Divergent Profile Kaviya sundar #1, Thanikaivel Murugan. D *2 # UG Degree holder, B.E. Aeronautical Engineering, Jeppiaar Engineering college, Chennai, India,

More information

AIRFLOW GENERATION IN A TUNNEL USING A SACCARDO VENTILATION SYSTEM AGAINST THE BUOYANCY EFFECT PRODUCED BY A FIRE

AIRFLOW GENERATION IN A TUNNEL USING A SACCARDO VENTILATION SYSTEM AGAINST THE BUOYANCY EFFECT PRODUCED BY A FIRE - 247 - AIRFLOW GENERATION IN A TUNNEL USING A SACCARDO VENTILATION SYSTEM AGAINST THE BUOYANCY EFFECT PRODUCED BY A FIRE J D Castro a, C W Pope a and R D Matthews b a Mott MacDonald Ltd, St Anne House,

More information

Aerodynamic study of a cyclist s moving legs using an innovative approach

Aerodynamic study of a cyclist s moving legs using an innovative approach Aerodynamic study of a cyclist s moving legs using an innovative approach Francesco Pozzetti 30 September 2017 Abstract During a period of four weeks in September, I completed a research project in fluid

More information

ZIN Technologies PHi Engineering Support. PHi-RPT CFD Analysis of Large Bubble Mixing. June 26, 2006

ZIN Technologies PHi Engineering Support. PHi-RPT CFD Analysis of Large Bubble Mixing. June 26, 2006 ZIN Technologies PHi Engineering Support PHi-RPT-0002 CFD Analysis of Large Bubble Mixing Proprietary ZIN Technologies, Inc. For nearly five decades, ZIN Technologies has provided integrated products and

More information

Journal of Engineering Science and Technology Review 6 (3) (2013) Research Article

Journal of Engineering Science and Technology Review 6 (3) (2013) Research Article Jestr Journal of Engineering Science and Technology Review 6 (3) (013) 105-110 Research Article JOURNAL OF Engineering Science and Technology Review www.jestr.org Lift and Drag on Cylinder of Octagonal

More information

2013 Wall of Wind (WoW) Contest Informational Workshop

2013 Wall of Wind (WoW) Contest Informational Workshop 2013 Wall of Wind (WoW) Contest Informational Workshop Presented By: Ioannis Zisis February 22, 2013 With Contributions By: Dr. Girma Bitsuamlak, Roy Liu, Walter Conklin, Dr. Arindam Chowdhury, Jimmy Erwin,

More information

Steady State Comparisons HAWC2 v12.5 vs HAWCStab2 v2.14: Integrated and distributed aerodynamic performance

Steady State Comparisons HAWC2 v12.5 vs HAWCStab2 v2.14: Integrated and distributed aerodynamic performance Downloaded from orbit.dtu.dk on: Jan 29, 219 Steady State Comparisons v12.5 vs v2.14: Integrated and distributed aerodynamic performance Verelst, David Robert; Hansen, Morten Hartvig; Pirrung, Georg Publication

More information

This is the author s final accepted version.

This is the author s final accepted version. Wang, Y., White, M., and Barakos, G.N. (2017) Wind-turbine wake encounter by light aircraft. Journal of Aircraft, 54(1), pp. 367-370. (doi:10.2514/1.c033870) This is the author s final accepted version.

More information

Methods The experiments were carried out in the wind tunnel in the Air physics laboratory at the Engineering Centre Bygholm as shown in figure 1.

Methods The experiments were carried out in the wind tunnel in the Air physics laboratory at the Engineering Centre Bygholm as shown in figure 1. 1 Standardisation of test method for salt spreader: Air flow experiments Report 2: Visualization of airflow patterns by Jan S. Strøm, Consultant Aarhus University, Engineering Centre Bygholm, Test and

More information

Influence of wing span on the aerodynamics of wings in ground effect

Influence of wing span on the aerodynamics of wings in ground effect Influence of wing span on the aerodynamics of wings in ground effect Sammy Diasinos 1, Tracie J Barber 2 and Graham Doig 2 Abstract A computational fluid dynamics study of the influence of wing span has

More information

Numerical simulations of a large offshore wind turbine exposed to turbulent inflow conditions

Numerical simulations of a large offshore wind turbine exposed to turbulent inflow conditions 9 th European Seminar OWEMES 2017 Numerical simulations of a large offshore wind turbine exposed to turbulent inflow conditions Galih Bangga, Giorgia Guma, Thorsten Lutz and Ewald Krämer Institute of Aerodynamics

More information

Effect of Upstream Velocity Gradient on the Formation of Sink Vortices in a Jet Engine Test Cell

Effect of Upstream Velocity Gradient on the Formation of Sink Vortices in a Jet Engine Test Cell Effect of Upstream Velocity Gradient on the Formation of Sink Vortices in a Jet Engine Test Cell W. H. Ho, H. Dumbleton, and M.C. Jermy Abstract Vortices can be produced and ingested into the intake of

More information

Numerical study of turbulent coherent structures and bubble entrainment under surfzone breaking waves

Numerical study of turbulent coherent structures and bubble entrainment under surfzone breaking waves Under consideration for publication in J. Fluid Mech. 1 Numerical study of turbulent coherent structures and bubble entrainment under surfzone breaking waves G A N G F E N G M A 1, J A M E S T. K I R B

More information

Numerical Studies on the Effect of Slotted Casing Treatment on the Performance of a Transonic Axial Flow Compressor

Numerical Studies on the Effect of Slotted Casing Treatment on the Performance of a Transonic Axial Flow Compressor Numerical Studies on the Effect of Slotted Casing Treatment on the Performance of a Transonic Axial Flow Compressor A. K. Shivayogi 1, Q. H. Nagpurwala 2 and M. D. Deshpande 3 1 - M. Sc. [Engg.] Student,

More information

The study on micro-location of wind-electric field in the complex terrain

The study on micro-location of wind-electric field in the complex terrain Academia Journal of Scientific Research 3(3): 000-000, February 2019 DOI: 10.15413/ajsr.2019.2006 ISSN 2315-7712 2019 Academia Publishing Research Paper The study on micro-location of wind-electric field

More information

Aerodynamic Measures for the Vortex-induced Vibration of π-shape Composite Girder in Cable-stayed Bridge

Aerodynamic Measures for the Vortex-induced Vibration of π-shape Composite Girder in Cable-stayed Bridge Aerodynamic Measures for the Vortex-induced Vibration of π-shape Composite Girder in Cable-stayed Bridge *Feng Wang 1), Jialing Song 2), Tuo Wu 3), and Muxiong Wei 4) 1), 2, 3), 4) Highway School, Chang

More information

VORTICITY CONCENTRATION AT THE EDGE OF THE INBOARD VORTEX SHEET

VORTICITY CONCENTRATION AT THE EDGE OF THE INBOARD VORTEX SHEET Submitted to the Journal of the American Helicopter Society VORTICITY CONCENTRATION AT THE EDGE OF THE INBOARD VORTEX SHEET J.M. Kim 1, N.M. Komerath 2, S.G. Liou 3 School of Aerospace Engineering Georgia

More information

The Effect of Gurney Flap Height on Vortex Shedding Modes Behind Symmetric Airfoils

The Effect of Gurney Flap Height on Vortex Shedding Modes Behind Symmetric Airfoils The Effect of Gurney Flap Height on Vortex Shedding Modes Behind Symmetric Airfoils Daniel R. Troolin 1, Ellen K. Longmire 2, Wing T. Lai 3 1: TSI Incorporated, St. Paul, USA, dan.troolin@tsi.com 2: University

More information

Increased Project Bankability : Thailand's First Ground-Based LiDAR Wind Measurement Campaign

Increased Project Bankability : Thailand's First Ground-Based LiDAR Wind Measurement Campaign Increased Project Bankability : Thailand's First Ground-Based LiDAR Wind Measurement Campaign Authors: Velmurugan. k, Durga Bhavani, Ram kumar. B, Karim Fahssis As wind turbines size continue to grow with

More information